Manufacturing method of hollow circuit board

Abstract

This invention provides a method for manufacturing a hollow circuit board, the manufacturing process of which involves a combination of specific steps, including the step of forming an insulating layer with a hollow pattern on a metal layer using a photosensitive resin. This improves upon the drawback of traditional hollow circuit boards where the insulating layer needs to be laser-cut to form insulating trenches in the later stage, thereby significantly reducing manufacturing costs.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a cutout circuit board, and more particularly to a method for manufacturing an energy-saving cutout circuit board. Background Technology

[0002] A cutout circuit board is a type of circuit board with holes in the inner or outer layers of a printed circuit board. It can achieve more connections and functions in a limited space, thus enabling thinner or smaller product designs compared to traditional circuit boards.

[0003] However, due to its higher technical requirements, the production and processing of cut-out circuit boards is more complex and costly than that of traditional printed circuit boards. Traditional cut-out circuit board manufacturing processes involve processing the cut-out areas of the insulating layer, commonly using die-cutting or laser cutting. However, these processing methods are inefficient, energy-intensive, and require higher manufacturing costs. Summary of the Invention

[0004] In view of the above-mentioned technical problems, the purpose of this invention is to provide a method for manufacturing a hollow circuit board that is energy-saving and cost-saving.

[0005] To achieve the above objectives, the present invention provides a method for manufacturing a cutout circuit board, comprising the following steps: providing a metal layer having an upper surface and a lower surface opposite to the upper surface; forming a patterned insulating layer on the upper surface, the patterned insulating layer including a first pattern and a first trench formed between the first patterns, and the patterned insulating layer being formed of a photosensitive resin; forming a first patterned dry film photoresist layer and a first unpatterned dry film photoresist layer on the upper and lower surfaces of the patterned insulating layer respectively, wherein a portion of the first patterned dry film photoresist layer is formed in the first trench, and the first patterned dry film photoresist layer includes a second pattern and a second trench formed between the second patterns; forming a first conductive line layer in the second trench; and removing the first patterned dry film photoresist layer and the first unpatterned dry film photoresist layer. A patterned dry film photoresist layer is formed to expose the space created after the removal of the second pattern and the lower surface of the metal layer; a second patternless dry film photoresist layer and a second patterned dry film photoresist layer are formed on the first conductive circuit layer and the lower surface, respectively, wherein a portion of the second patternless dry film photoresist layer is formed in the space, and the second patterned dry film photoresist layer includes a third pattern and a third trench formed between the third patterns, and the third trench corresponds to the first trench; the metal layer is etched through the second patterned dry film photoresist layer to form a second conductive circuit layer, wherein the second conductive circuit layer has a fourth trench, and the fourth trench communicates with the first trench and the third trench; and the second patternless dry film photoresist layer and the second patterned dry film photoresist layer are removed to obtain a cutout circuit board.

[0006] Preferably, the photosensitive resin comprises a photosensitive epoxy resin, a photosensitive polyphenyloxazole, or a photosensitive polyimide.

[0007] Preferably, the method for forming the patterned insulating layer includes the following steps: forming a photosensitive insulating layer; and sequentially exposing, developing, and baking the photosensitive insulating layer to form the patterned insulating layer. More preferably, the photosensitive insulating layer is formed by screen printing, coating, spraying, rolling, or lamination.

[0008] Preferably, the first patterned dry film photoresist layer is formed by attaching a dry film photoresist and then sequentially exposing and developing the dry film photoresist.

[0009] Preferably, the first patternless dry film photoresist layer is formed by attaching a dry film photoresist, then exposing the entire surface of the dry film photoresist and then developing it.

[0010] Preferably, the second patternless dry film photoresist layer is formed by attaching a dry film photoresist, exposing the entire surface of the dry film photoresist, and then developing it.

[0011] Preferably, the second patterned dry film photoresist layer is formed by attaching a dry film photoresist and then sequentially exposing and developing the dry film photoresist.

[0012] Preferably, the thickness of the metal layer is between 12 and 72 micrometers.

[0013] Preferably, the thickness of the patterned insulating layer is between 5 and 40 micrometers.

[0014] The present invention also provides a method for manufacturing a cutout circuit board, comprising the following steps: providing a layered structure comprising: a first patternless dry film photoresist layer; a metal layer disposed on the first patternless dry film photoresist layer; a patterned insulating layer disposed on the metal layer, wherein the patterned insulating layer includes a first pattern and a first trench formed between the first pattern, and the patterned insulating layer is formed of a photosensitive resin; a first patterned dry film photoresist layer, wherein a portion of the first patterned dry film photoresist layer is disposed in the first trench, and the first patterned dry film photoresist layer includes a second pattern and a second trench formed between the second pattern; A first conductive circuit layer is disposed within the second trench; the first patterned dry film photoresist layer and the first unpatterned dry film photoresist layer are removed to expose the space formed after the removal of the second pattern and the lower surface of the metal layer; a second unpatterned dry film photoresist layer and a second patterned dry film photoresist layer are respectively covered on the upper and lower surfaces of the first conductive circuit layer, wherein the second patterned dry film photoresist layer includes a third pattern and a third trench formed between the third pattern, and the third trench corresponds to the first trench; the metal layer is etched through the second patterned dry film photoresist layer to form a second conductive circuit layer, wherein the second conductive circuit layer has a fourth trench, and the fourth trench communicates with the first trench and the third trench; and the second unpatterned dry film photoresist layer and the second patterned dry film photoresist layer are removed to obtain a cutout circuit board.

[0015] The present invention further provides a hollow circuit board, comprising: a first conductive line layer having trenches; a second conductive line layer having trenches; and a patterned insulating layer disposed between the first conductive line layer and the second conductive line layer, wherein the patterned insulating layer has trenches, wherein the trenches of the first conductive line layer, the trenches of the second conductive line layer and the trenches of the patterned insulating layer are connected, the patterned insulating layer is formed of a photosensitive resin, and the trenches of the patterned insulating layer are formed by exposing the photosensitive resin and then developing it.

[0016] Preferably, the thickness of the patterned insulating layer is between 5 and 40 micrometers.

[0017] According to the present invention, a method for manufacturing a hollow circuit board with a simpler manufacturing process, greater energy saving, and lower manufacturing cost can be obtained. Attached Figure Description

[0018] Figures 1A to 1K This is a schematic flowchart illustrating the manufacturing method of a hollow circuit board according to an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of a hollow circuit board according to an embodiment of the present invention.

[0020] Figure label:

[0021] Detailed Implementation

[0022] In this invention, if the terms "first" and "second" are used to describe a component, the component is not limited by the terms, and they are mainly used to distinguish one component from another.

[0023] This invention provides a method for manufacturing a cutout circuit board, comprising the following steps: providing a metal layer having an upper surface and a lower surface opposite to the upper surface; forming a patterned insulating layer on the upper surface, the patterned insulating layer including a first pattern and a first trench formed between the first patterns, and the patterned insulating layer being formed of a photosensitive resin; forming a first patterned dry film photoresist layer and a first unpatterned dry film photoresist layer on the upper and lower surfaces of the patterned insulating layer respectively, wherein a portion of the first patterned dry film photoresist layer is formed in the first trench, and the first patterned dry film photoresist layer includes a second pattern and a second trench formed between the second patterns; forming a first conductive line layer in the second trench; and removing the first patterned dry film photoresist layer and the first unpatterned dry film photoresist layer. A photoresist layer is formed to expose the space created after the removal of the second pattern and the lower surface of the metal layer; a second patternless dry film photoresist layer and a second patterned dry film photoresist layer are formed on the upper and lower surfaces of the first conductive line layer, respectively, wherein a portion of the second patternless dry film photoresist layer is formed in the space, and the second patterned dry film photoresist layer includes a third pattern and a third trench formed between the third pattern, and the third trench corresponds to the first trench; the metal layer is etched through the second patterned dry film photoresist layer to form a second conductive line layer, wherein the second conductive line layer has a fourth trench, and the fourth trench communicates with the first trench and the third trench; and the second patternless dry film photoresist layer and the second patterned dry film photoresist layer are removed to obtain a cutout circuit board.

[0024] The present invention further provides a method for manufacturing a hollow circuit board, comprising the following steps: providing a layered structure comprising: a first patternless dry film photoresist layer; a metal layer disposed on the first patternless dry film photoresist layer; a patterned insulating layer disposed on the metal layer, wherein the patterned insulating layer includes a first pattern and a first trench formed between the first pattern, and the patterned insulating layer is formed of a photosensitive resin; a first patterned dry film photoresist layer, a portion of the first patterned dry film photoresist layer being disposed in the first trench, and the first patterned dry film photoresist layer including a second pattern and a second trench formed between the second pattern; and a first conductive line layer disposed in the second trench; removing the first patterned dry film photoresist layer and the first patterned dry film photoresist layer. A first patternless dry film photoresist layer is used to expose the space formed after the removal of the second pattern and the lower surface of the metal layer; a second patternless dry film photoresist layer and a second patterned dry film photoresist layer are respectively covered on the upper and lower surfaces of the first conductive circuit layer, wherein the second patterned dry film photoresist layer includes a third pattern and a third trench formed between the third pattern, and the third trench corresponds to the first trench; the metal layer is etched through the second patterned dry film photoresist layer to form a second conductive circuit layer, wherein the second conductive circuit layer has a fourth trench, and the fourth trench communicates with the first trench and the third trench; and the second patternless dry film photoresist layer and the second patterned dry film photoresist layer are removed to obtain a cutout circuit board.

[0025] The manufacturing method of the hollow circuit board provided by the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0026] The manufacturing method of the hollow circuit board 100 provided in this embodiment of the invention includes the following steps.

[0027] Step S1, please refer to Figure 1A A metal layer 10 is provided, the metal layer having an upper surface 10a and a lower surface 10b opposite to the upper surface.

[0028] In this embodiment, the thickness of the metal layer 10 is between 12 and 72 micrometers. In this embodiment, the metal layer 10 is made of copper. In some embodiments, the metal layer 10 is made of an alloy. In some embodiments, the metal layer 10 is made of other metals.

[0029] Step S2, as follows Figure 1BAs shown, a photosensitive insulating layer 20 is formed on the upper surface 10a using a photosensitive resin. The formation method is not particularly limited and can be a liquid wet process, including screen printing, coating, and spraying; it can also be a process for dry film-like photosensitive insulating materials, including rolling and lamination. The photosensitive resin can be a photosensitive epoxy resin, a photosensitive polyphenyloxazole (PSPBO), or a photosensitive polyimide (PSPI). In this embodiment, the photosensitive resin is a photosensitive polyimide.

[0030] Step S3 involves sequentially exposing, developing, and baking the photosensitive insulating layer 20 to form a patterned insulating layer 30. For example... Figure 1C As shown, the patterned insulating layer 30 includes a first pattern 32 and first trenches 35 formed between the first patterns 32. After curing (baking temperature 150~200℃), the photosensitive insulating layer 20 has high temperature resistance and chemical solvent resistance, and can withstand high temperatures of 150~320℃. In this embodiment, the thickness of the patterned insulating layer 30 is between 5 and 40 micrometers.

[0031] For step S4, please refer to [link / reference]. Figure 1D Dry film photoresist 40 and dry film photoresist 50 are respectively attached to the lower surface 10b of the patterned insulating layer 30 and the metal layer. In this invention, the attachment order of the dry film photoresist 40 and dry film photoresist 50 is not limited. In some embodiments, the dry film photoresist 40 is attached first, followed by the dry film photoresist 50. In some embodiments, the dry film photoresist 50 is attached first, followed by the dry film photoresist 40. In this embodiment, the dry film photoresist 40 and dry film photoresist 50 are attached simultaneously, which simplifies the manufacturing process. In this invention, the dry film photoresist 40 and dry film photoresist 50 may be the same or different.

[0032] For step S5, please refer to [link / reference]. Figure 1E The dry film photoresist 40 is exposed with the desired pattern and then developed to obtain a first patterned dry film photoresist layer 42 formed on the patterned insulating layer 30; the entire surface of the dry film photoresist 50 is exposed and then developed to obtain a first unpatterned dry film photoresist layer 52 formed on the lower surface 10b. The photoresist layer 52 serves as a resist for plating. Figure 1E As shown, the first patterned dry film photoresist layer 42 includes a second pattern 44 and a second trench 46 formed between the second patterns, and the photoresist layer 42 is partially formed in the first trench 35.

[0033] Step S6, please refer to Figure 1FA first conductive line layer 60 is formed in the second trench 46. In this embodiment, the specific steps for forming the first conductive line layer 60 are as follows: a seed layer is formed in the second trench 46 on the surface of the patterned insulating layer 30 by sputtering or electroless electroplating, and then the first conductive line layer 60 is formed by electroplating.

[0034] For step S7, please refer to [link / reference]. Figure 1G The first patterned dry film photoresist layer 42 and the first unpatterned dry film photoresist layer 52 are removed to expose the space 65 formed after the removal of the second pattern 44 and the lower surface 10b of the metal layer. In this embodiment, the first patterned dry film photoresist layer 42 and the first unpatterned dry film photoresist layer 52 are removed simultaneously. In some embodiments, the first patterned dry film photoresist layer 42 is removed first, followed by the first unpatterned dry film photoresist layer 52. In some embodiments, the first unpatterned dry film photoresist layer 52 is removed first, followed by the first patterned dry film photoresist layer 42.

[0035] Step S8, please refer to Figure 1H Dry film photoresist 70 and dry film photoresist 80 are respectively attached to the first conductive circuit layer 60 and the lower surface 10b of the metal layer. In this invention, the attachment order of the dry film photoresist 70 and dry film photoresist 80 is not limited. In some embodiments, the dry film photoresist 70 is attached first, followed by the dry film photoresist 80. In some embodiments, the dry film photoresist 80 is attached first, followed by the dry film photoresist 70. In this embodiment, the dry film photoresist 70 and dry film photoresist 80 are attached simultaneously, which simplifies the manufacturing process. In this invention, the dry film photoresist 70 and dry film photoresist 80 may be the same or different. In this invention, dry film photoresist 40, dry film photoresist 50, dry film photoresist 70, and dry film photoresist 80 may be the same or different.

[0036] For step S9, please refer to [link / reference]. Figure 1I The entire surface of the dry film photoresist 70 is exposed and then developed to obtain a second patternless dry film photoresist layer 72 formed on the first conductive circuit layer 60; the dry film photoresist 80 is exposed with the desired pattern and then developed to obtain a second patterned dry film photoresist layer 82 formed on the lower surface 10b. The second patternless dry film photoresist layer 72 has a plating resistance function. Figure 1I As shown, the second patterned dry film photoresist layer 82 includes a third pattern 84 and a third trench 86 formed between the third patterns, and the third trench 86 corresponds to the first trench 35.

[0037] Step S10, please refer to Figure 1JThe metal layer 10 is etched via the second patterned dry film photoresist layer 82 to form a second conductive line layer 90, wherein the second conductive line layer 90 is provided with a fourth trench 92, and the fourth trench 92 is connected to the first trench 35 and the third trench 86.

[0038] Step S11, please refer to Figure 1K Remove the second unpatterned dry film photoresist layer 72 and the second patterned dry film photoresist layer 82 to obtain a cutout circuit board 100, wherein the fourth trench 92 is connected to the first trench 35 and the space 65.

[0039] Based on the above manufacturing method, the present invention further provides a cutout circuit board. Please refer to Figure 2, which is a schematic diagram of a cutout circuit board according to an embodiment of the present invention. The cutout circuit board 200 includes: a first conductive line layer 60 having trenches 67; a second conductive line layer 90 having trenches 92; and a patterned insulating layer 30 disposed between the first conductive line layer 60 and the second conductive line layer 90. The patterned insulating layer 30 includes a first pattern 32 and trenches 35 forming the first pattern. The trenches 67 of the first conductive line layer 60, the trenches 92 of the second conductive line layer 90, and the trenches 35 of the patterned insulating layer 30 are connected. The patterned insulating layer 30 is formed of a photosensitive resin, and the trenches 32 of the patterned insulating layer 30 are formed by exposing the photosensitive resin and then developing it. In this embodiment, the thickness of the patterned insulating layer is between 5 and 40 micrometers.

[0040] As can be seen from the above, the present invention uses photosensitive development patterns to form hollow areas in the insulating layer, which can remove the insulating layer to form hollow areas without complicated processing steps. Therefore, it is simpler and less expensive than traditional manufacturing methods. In particular, the manufacturing method of the present invention does not require complicated laser cutting, which not only saves energy and reduces costs, but also greatly improves the production efficiency of hollow circuit boards.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for manufacturing a cutout circuit board, comprising the following steps: A metal layer is provided, the metal layer having an upper surface and a lower surface opposite to the upper surface; A patterned insulating layer is formed on the upper surface, the patterned insulating layer including a first pattern and a first groove formed between the first pattern, and the patterned insulating layer is formed of a photosensitive resin; A first patterned dry film photoresist layer and a first unpatterned dry film photoresist layer are formed on the upper and lower surfaces of the patterned insulating layer, respectively. A portion of the first patterned dry film photoresist layer is formed in the first trench, and the first patterned dry film photoresist layer includes a second pattern and a second trench formed between the second patterns. A first conductive line layer is formed within the second trench; Remove the first patterned dry film photoresist layer and the first unpatterned dry film photoresist layer to expose the space formed after the removal of the second pattern and the lower surface of the metal layer. A second patternless dry film photoresist layer and a second patterned dry film photoresist layer are formed on the upper and lower surfaces of the first conductive line layer, respectively. A portion of the second patternless dry film photoresist layer is formed in the space, and the second patterned dry film photoresist layer includes a third pattern and a third trench formed between the third patterns, and the third trench corresponds to the first trench. The metal layer is etched via the second patterned dry film photoresist layer to form a second conductive line layer, wherein the second conductive line layer has a fourth trench and the fourth trench is connected to the first trench and the third trench. and Remove the second unpatterned dry film photoresist layer and the second patterned dry film photoresist layer to obtain a cutout circuit board.

2. The manufacturing method according to claim 1, wherein the photosensitive resin comprises a photosensitive epoxy resin, a photosensitive polyphenyloxazole, or a photosensitive polyimide.

3. The manufacturing method of claim 1, wherein the method for forming the patterned insulating layer comprises the following steps: Forming a photosensitive insulating layer; and The photosensitive insulating layer is sequentially exposed, developed, and baked to form the patterned insulating layer.

4. The manufacturing method of claim 3, wherein the photosensitive insulating layer is formed by screen printing, coating, spraying, rolling or lamination.

5. The manufacturing method of claim 1, wherein the first patterned dry film photoresist layer is formed by attaching a dry film photoresist and then sequentially exposing and developing the dry film photoresist.

6. The manufacturing method of claim 1, wherein the first patternless dry film photoresist layer is formed by attaching a dry film photoresist, then exposing the entire surface of the dry film photoresist and then developing it.

7. The manufacturing method of claim 1, wherein the second patternless dry film photoresist layer is formed by attaching a dry film photoresist, then exposing the entire surface of the dry film photoresist and then developing it.

8. The manufacturing method of claim 1, wherein the second patterned dry film photoresist layer is formed by attaching a dry film photoresist and then sequentially exposing and developing the dry film photoresist.

9. The manufacturing method of claim 1, wherein the thickness of the metal layer is between 12 and 72 micrometers.

10. The manufacturing method of claim 1, wherein the thickness of the patterned insulating layer is between 5 and 40 micrometers.

11. A method for manufacturing a cutout circuit board, comprising the following steps: Provides a layered structure comprising: First patternless dry film photoresist layer; A metal layer is disposed on the first patternless dry film photoresist layer; A patterned insulating layer is disposed on the metal layer, and the patterned insulating layer includes a first pattern and a first trench formed between the first pattern, and the patterned insulating layer is formed of a photosensitive resin; A first patterned dry film photoresist layer, a portion of which is disposed in the first trench, and the first patterned dry film photoresist layer includes a second pattern and a second trench formed between the second patterns. and A first conductive circuit layer is disposed within the second trench; Remove the first patterned dry film photoresist layer and the first unpatterned dry film photoresist layer to expose the space formed after the removal of the second pattern and the lower surface of the metal layer. A second unpatterned dry film photoresist layer and a second patterned dry film photoresist layer are respectively covered on the upper and lower surfaces of the first conductive circuit layer, wherein the second patterned dry film photoresist layer includes a third pattern and a third trench formed between the third pattern, and the third trench corresponds to the first trench. The metal layer is etched via the second patterned dry film photoresist layer to form a second conductive line layer, wherein the second conductive line layer has a fourth trench and the fourth trench is connected to the first trench and the third trench. and Remove the second unpatterned dry film photoresist layer and the second patterned dry film photoresist layer to obtain a cutout circuit board.

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